The present invention relates to a swinging blade guard assembly for a motor driven saw blade, and more particularly, a swinging blade guard assembly that provides controlled exposure of the saw blade, as may be desired, from an upper at rest to a lower operational position.
Powered or compound miter saws are used for the miter and bevel cutting of wood, metals, and plastics in a variety of industries. For example, in the construction industry, moldings, door frames, chair rails and the like must be miter cut at the corners, and in addition, a combined miter/bevel cut is required in certain instances for the proper fitting of parts. In such powered or compound miter saws, blade guards are used to enclose the blade, typically an upper fixed blade guard and a lower swinging blade guard that uncovers the rotating motor driven saw blade when moved from the upper at rest to a lower operational position where cutting of the workplace takes place.
The present invention is directed specifically to a new and improved swinging blade guard assembly which overcomes some of the problems associated with prior art devices. Examples of powered miter saws with swinging blade guards are shown, for example, in U.S. Pat. Nos. 4,805,504 and 5,020,406. In each of these patents, the lower portion of the motor driven saw blade is fully covered when the motor driven saw blade is in an upper at rest position. Each of these patents also rotate the lower guard during the downward or operational stroke of the motor driven saw blade to its cutting position.
One of the problems associated with the swinging blade guard assemblies of the prior art is that the swinging blade guard does not rotate rapidly enough during the first part of the downstroke of the motor driven saw blade, in order to enable the swinging blade guard to clear a workpiece, especially when performing a bevel cut. At the same time, the swinging blade guard should not rotate so far that it exposes the front of the motor driven saw blade above the workpiece, any more than necessary. The prior art is thus restricted because it does not provide variable or controlled exposure of the motor driven saw blade during various phases of the downward or operational stroke of the motor driven saw blade particularly, in connection with bevel cuts for which they were not designed.
The present invention overcomes the problems associated with the prior art for powered miter saws and other types of motor driven saw blades used in other types of saw constructions which are moved from an upper to a lower position in cutting workpieces.